Anand R, Wilkinson J M, Kellie S
Department of Biochemical Pharmacology, William Harvey Research Institute, Medical College of St. Bartholomew's Hospital, London, UK.
Oncogene. 1993 Nov;8(11):3013-20.
In platelets, pp60c-src has been variously localised to cytosol, dense bodies, or plasma membrane and surface-connected canalicular membranes. We have investigated the localisation of pp60c-src in highly purified human platelet subcellular fractions isolated using density gradient centrifugation and continuous flow electrophoresis followed by quantitative immunoblotting. We have obtained fractions enriched in surface membranes and alpha granule membranes as assessed by the presence of the marker proteins gpIb, gpIIb, thrombospondin, fibrinogen and fibronectin. Quantitative immunoblotting demonstrated that most of the cellular pp60c-src co-purified with markers for surface membrane components and that unlike the situation in fibroblasts, platelet pp60c-src did not associate with non-granule intracellular membranes such as Golgi, endoplasmic reticulum and endosomes. A small subpopulation of the total cellular pp60c-src co-purified with granule components or dense body markers, however this occurred in proportion to the presence of surface membrane markers. Our results demonstrate that the majority of platelet pp60c-src is located on the cytoplasmic face of the plasma membrane in human platelets.
在血小板中，pp60c-src定位于胞质溶胶、致密体或质膜以及表面连接的小管膜。我们使用密度梯度离心和连续流电泳分离出高度纯化的人血小板亚细胞组分，随后进行定量免疫印迹，研究了pp60c-src的定位。通过标记蛋白gpIb、gpIIb、血小板反应蛋白、纤维蛋白原和纤连蛋白的存在评估，我们获得了富含表面膜和α颗粒膜的组分。定量免疫印迹表明，大多数细胞内的pp60c-src与表面膜成分的标记物共同纯化，并且与成纤维细胞的情况不同，血小板pp60c-src不与高尔基体、内质网和内体等非颗粒细胞内膜相关联。然而，总细胞pp60c-src的一小部分亚群与颗粒成分或致密体标记物共同纯化，但这种情况与表面膜标记物的存在成比例。我们的结果表明，人血小板中大多数血小板pp60c-src位于质膜的细胞质面上。
